Process of making incandescent lamps.



PATENTED JAN. 23, 1906. P.H.BLAOKBURN.

PROCESS OF MAKING INGANDESOENT LAMPS. APPLIOATION FILED MAR.2, 1905.

Win 6666 mww v thetubes and many of the and blown off by a puff of air blown into said UNITED STATES PATENT OFFICE.

FRANK H. BLACKBURNfOF FOSTORIA, OHIO, ASSIGNOR TO THE NATIONAL ELECTRIC LAMP COMPANY, OF CLEVELAND, OHIO, A CORPORATION or NEW JERSEY.

Specification of Letters Patent.

Application filed March 2, 1905. Serial No. 248,023-

To all whom it may concern:

Be it known that I, FRANK H. BLACKBURN, a citizen of the United'States, residing at Fostoria, in the county of Seneca and State of Ohio, have invented a certain new and useful Improvement in Processes of Making Incandescent Lamps, of which the following is a full, clear, and exact description, reference being had to the accompanying draw 1ngs.-

This invention is a process by which to construct from the globe as it comes from the glass-blower a -certain tipless incandescent lamp ready to have the air exhausted therefrom.

The lamp which this process is intended to make is substantially that which forms the subject-matter of my application, Serial No.

187 ,887 filed January 6, 1904. r In endeavoring to make such a lamp commercially by methods employed for making ordinary incandescent lamps the breakage WtlSflPPiLlling. The globes for all lamps are blown and come from the glass-blower with a lon neck attached, the gre'aterportion of which as to be removed.- The usual process for the removal of this surplus neck is to hold the bulb with the neck down and rotate it' on a vertical axis while a blowpipe flame lays against it. As the glass softens the nec below this lane settles down and finally drops off, andt e hot edges of the neck coming into contact seal themselves together. Then the tubulation tube, which was previousl attached to the top of the globe, is use for blowing off the end of the hot sealed neck.

In constructing the tipless lamp described in the a plication above referred to it is not permissi le to attach a tubulation-tube at any point except the neck. It was found that when such a tube was attached so as to pro'ect laterally from the neck before the nec was blown off it was practically impossible to handle such lobe and to subject it to the various and su sequent manipulations without breaking a very large percentage of g obes.

I have discovered, but it appears not to have been suspected by any one before, that when a sealed neck havin a small hole through it is heated below sald hole and softened this softened portion can be expanded hole from a nozzle or tube having no connection or even contact with the globe.

In practicing my invention on bulbs as they come from the lass blower the following operations are per or'medi First, forming a small hole in the neck; second, sing off the surplus neck and sealing together the'edges of that part of the neck WhlCh is not' removed; third, blowing a puff of air onto saidhole through a nozzle or tubewhich is entirely PatentedJ'an. 28, 1906. v

independent of the bulb; fourth, sealing in the mount, and, fifth, sealing an exhaustin tube to the neck over the aforesaid ho e therein, and, finally, after the air has been.

exhausted from the bulb sealing off of this exhaust ing-tube.

In the drawings, Figure 1 represents the globe A after it has been subjected to the first stepviz., the formation of the small hole a in the neck. Fig. 2 represents the globe after the redundant part of the neck has been sealed off. Fig. 3 shows in what manner .the third step of the process maybe carried out viz., by blowing throu h an independent tube D- onto the hole in t e neckwhereby the softened sealed end a of the neck is expanded and exploded. Fig, 4 represents the bulb "after this step has been performed. Fig; 5'

represents the lamp after the mount E been sealed onto the same. Fig. 6 represents the lam after the exhaustion-tube F has been sea ed onto the same over the hole a in the neck. Fig. 7 represents the lamp after the air has been exhausted from the globe and the tube F sealed off at a}.

I claim 1. The process of .making incandescent lamps consisting in forming an opening into the globe-substantiall at the surface thereof,

heating the neck of t e globe to seal off the end thereof, then applying to such opening a tube separate from the globe and forcing pressure through the tube to blow off the end of the globe.

2. The process "of. making incandescent lamps consisting of taking a globe having an open neck, formingan opening into it Without substantial projection thereat, sealing off by heat.the neck of the globe, then applying to the opening a tube unsealed thereto, and by air-pressure through the tube blowing off the end of the globe to free it.

3. The process of-making tipless incandescent lamps consisting in taking a globe having a neck, forming a small opening in it near the point Where the neck joins the globe proper, sealing ofi by heat the neck of the globe just below such opening, then blowing air into the lobe through such openin by means of a tu e unsealed thereto the air b lowing oil the end of the neck.

4. The process of making tipless incandescent lamps consisting in taking a globe having a neck, forming a small opening into it near the point where the neck joins the globe proper, sealing off by heat the neck of the globe just below such opening, then blowing air into the globe through such opening by means of a tube unsealed thereto, the air blowing off the end of the neck, then placing the filament and its support in the globe, fusing the support to the globe below such opening, and then fusing a tube to the opening.

5. The process of making incandescent lamps consisting in forming a small hole in the neck, fusing ofi the surplus neck and sealing together the edges of that part which is not removed, blowing a pufi of air into said hole through a tube which is independent of the bulb, sealing in the mount, and sealing an exhausting-tube to the neck over the aforesaid hole.

In testimony whereof I hereunto affix my signature in the presence of two Witnesses.

FRANK H. BLACKBURN. 

